1. Field
Embodiments discussed herein generally relate to a medical device used to facilitate the transfer of fluid from a fluid source to a patient, and more specifically, to a retention member used in the medical device, such as an intravenous (IV) catheter introducer assembly, for the prevention of blood backflow and blood leakage.
2. Relevant Art
Health care practitioners administering a catheter will locate the tip of a catheter needle in a vein or artery of the patient. When the needle tip is properly located, a small flow or flash of blood occurs through the hollow needle and into the flash or hub chamber at the proximal end of the needle. The health care practitioner notes the presence of blood in the flash chamber as an indication of proper needle placement, and then advances the catheter into the vascular system and withdraws the needle from the patient, leaving the catheter in place in the blood vessel.
As the needle tip moves to a location proximal of the distal end of the catheter tube, blood also flows under venous or arterial pressure into the catheter. Typically, blood enters the annular space between the outer surface of the needle and the inner wall of the catheter cannula or tube. To a practitioner, this blood flow into the annular space between the needle and the catheter tube confirms successful catheter placement and is typically a quicker feedback than verifying blood in the flash chamber of the needle hub. Usually, this “backflow” of blood is of no consequence because the catheter hub is quickly connected to a tubing set once the needle is withdrawn from the catheter. However, catheters with, for example, needle guards and the like that occupy the catheter hub may become contaminated by the backflow of blood prior to the complete withdrawal of the needle. A contaminated needle guard, for example, subjects health care practitioners to undesirable contact with the patient's blood.
To remedy the possibility of undesirable contact with the patient's blood, many catheters employ plugs, caps or valves, which may be collectively referred to as plug or plugs, to seal the catheter hub from the catheter cannula. However, some of these plugs are not effective to reliably evacuate air, which is needed to allow for the effective flash flow of blood through the space between the catheter tube and the needle. Consequently, it has been a problem to produce a plug that is effective to exhaust air while obviating blood loss following puncture of the vein. In some previously developed air bleeding plugs, only a single narrow opening is provided, which may be so oriented or clogged as to not permit the adequate evacuation of air from the interior of the IV catheter assembly. A clogged or plugged air passage is analogous to requiring blood flow to flow into a dead space.